I've got a MacBook Air running Mountain Lion, and have attached an external 24" monitor. I want to run both displays, and have multiple spaces available as well, but I'm struggling to find a way to get a better setup.

Essentially, I want my 24" display to be my 'primary display', where I do most of my work. I then want to use my MBA display to run things like tweetdeck, Reeder, etc. On that MBA display, I want to run tweetdeck and Reeder at full screen, and be able to swipe between two spaces while not disturbing the 24" monitor screen. Is that even possible? Are there 3rd party utilities that would allow for this setup?

Basically, I'm looking to be able to swipe spaces on the MBA monitor, but not the 24"